Area Codes

At some point I heard an interesting piece of trivia about the initial assignment of area codes. With rotary phones, the time it takes to dial a digit is actually a function of the digit itself (dialing a 2 takes twice as much time as dialing a 1, dialing a 0 takes 10 times as long as dialing a 1, etc.).

Keeping this in mind, the people who initially laid out the area codes allocated them as a function of population or importance.

Intrigued, I munged a web page to give me an ordering of all the area codes based on number of pulses (i.e., sum of digits counting 0 as 10).

The top few are as follows:

5 - 212 NY New York (New York City Manhattan area, overlays with 646 and 917)
6 - 213 CA California (Downtown Los Angeles area only)
6 - 231 MI Michigan (Traverse City, Ludington, Muskegon, Petoskey and northwestern Michigan)
6 - 312 IL Illinois (downtown central Chicago area)
6 - 321 FL Florida (Orlando, Cocoa Beach, St Cloud and central eastern Florida, overlays with 407)
7 - 214 TX Texas (Dallas area, overlays with 469 and 972)
7 - 313 MI Michigan (Dearborn, Detroit and inner Detroit suburbs)
7 - 412 PA Pennsylvania (Pittsburgh area, McKeesport, Braddock, Duquesne, overlays with 878)
8 - 215 PA Pennsylvania (Philadelphia area, overlays with 267 and 445)
8 - 224 IL Illinois (Waukegan, Des Plaines, northwest Chicago suburbs and northeastern Illinois, overlays with 847)
8 - 251 AL Alabama (Mobile, Jackson and southwestern Alabama)
8 - 314 MO Missouri (St Louis, Florissant, Crestwood, Affton and surrounding suburbs)
8 - 323 CA California (Florence and Los Angeles excluding downtown Los Angeles)
8 - 413 MA Massachusetts (Pittsfield, Springfield, Holyoke, Greenfield and western Massachusetts)
8 - 512 TX Texas (Austin, Lampasas, Bastrop, Milam and central Texas)

The bottom few are:

27 - 908 NJ New Jersey (Washington, Elizabeth, Warren, Plainfield and west central New Jersey)
27 - 980 NC North Carolina (Charlotte, Kingstown and south central North Carolina, overlays with 704)
28 - 909 CA California (San Bernardino, Ontario, Pomona, Chino, Arrowhead and Big Bear Lake areas)

I'm guessing they came along later, but it is fun to think of Elizabeth, NJ as, basically, the least interesting place in the US.

Random. Anyway.


Posted Apr 22 2006, 04:40 PM by mike-vernal
Filed under:

Comments

Brian A. Randell wrote re: Area Codes
on 04-25-2006 7:34 AM
Yes, the '909' came along much later (~1992 IIRC). Up until then it was part of 714--Orange County. 909 recently (~2004 IIRC) was overlayed with 951 also.
Don Box wrote re: Area Codes
on 05-19-2006 1:01 AM
I'm pretty sure that the original design required the 2nd digit of the area code to be a One or Zero.

Back in the 1960's (when I learned to dial a telephone), inter-areacode calls did not use today's "1-" prefix. I believe they relied on the 2nd digit being 0 or 1 to indicate whether you were calling out of your area code or not.

The addition of "1-" happened (I think) in the late 1960's or early 1970's to allow area codes to have an arbitrary 2nd digit.

DB
Yoda wrote re: Area Codes
on 07-04-2006 8:39 PM
Don is absolutely correct. Also, when "direct distance dialing" was invented in 1951 (see http://www.att.com/attlabs/reputation/timeline/51trans.html), 212 was all of New York City, not just Manhattan, and it was still that way when I moved to NYC in 1972. 310 being split off from 213 in Los Angeles and 908 being split off from 201 in northern New Jersey came much later.

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